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Stumbled across some pics of these about 2 weeks ago, and thought it would be cool to make one. CNC makes routing the slots pretty painless. I routed a pocket for a 1"-8 hex nut, and epoxied it in place. Back and hub body are 3/4" baltic birch, and the front plate is 1/4" MDF. Only problem is that when epoxying the nut in, its a bit tricky (nearly impossible) to get the nut perfectly perpendicular to the face. I fixed that by building a jig and surfacing the face with a router while it was spinning on the lathe. I've figured out how to correct this for the next one.

Anyway, it actually works pretty good. Here's a video of it spinning a rough bowl.

Gallery

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Wow, Gerry- THANK YOU!!!!!

I have been looking for something like this for a long time. The chuck I made has straight slots and is constantly releasing the work as it spins. This will solve that problem. Off to the shop!!

Lew
 

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Hey Gerry. I like this chuck. It looks really flexible because it adjusts to any size. The only thing I wonder about (and this is not a sly way to criticize) is about getting the workpiece properly centered. I suppose you could just deduct the diameter of your bowl from the diameter of the chuck, but I'm thinking about getting all those handles tightened in an accurate position. How do you do it?
 

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It's self centering. the slots on the front and back go in different direction, so as you turn the discs, the stops move in and out. Google Longworth Chuck and you'll find more info.
 

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Wow, I didn't even notice the slots went the other way until your reply to Mike. Now I see why you made a front piece and back piece. I thought it was just layers. That's really cool.
 

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Thanks much Gerry. Self centering is good.
 

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Hey Gerry I searched the net for Longworth lathe chuck plans and it's been chemically rinsed of any actual plans that I could find. I did find a list of materials needed and some construction instructions but only one outline drawing of the outside of the faceplate. Have you a specific source for plans? Thanks for any help.
 

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Found this site that has some construction information.

Lew
 

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That's where I got some of my info from, including the idea to use the nut, rather than a faceplate. Much cheaper. I wish he'd shown how he mounted the nut, though. I didn't want mine to blow apart, so I used a 2-5/8" diameter hub. This limits me to holding a 3" part inside the jaws, and about 5" on the outside. His looks like it goes a lot smaller.
 

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The lathe is turning the wrong way.
It should turn toward you unless you are really small and can shimmy in againt the wall. <g>
It looks to me like you have your "bowl chucker" mounted on the wrong side of the slots

Oh, and the bowl is not centered so if you do decide to tool it you are going to end up perforating it or having an out of round edge at least.

Regards

Bob
 

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I have looked at these a dozen time on the net…. But for the first time i see that the slots run in different directions to make this self centering…...... I guess I need to look at things like this a bit closer…. Duh !!!!
 

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Bob, the headstock on my lathe is turned around away from the bed. I inadvertently made the chuck too big, so had to turn the headstock around to mount it.
 

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And the "bowl" is solid, and is actually not really round. I rough turned it when it was wet, and it's been lying in the garage for several months. I wasn't actually able to finish turning it, as the spalting is too soft.
 

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Thanks a load Lew and Gerry. I went to the article. I am definitely going to make one soon as possible. I have the materials I need already. I just need to get the hardware.
 

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Ger21
"I wasn't actually able to finish turning it, as the spalting is too soft"
I wondered about that too.

The problem here is that with 14,000 "inerested viewers that if you don't clarify these things on your post it is possible that an unknowiing beginner will copy exaclty what he sees in the pictures.

Regards

Bob
 

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Great addition to the lathe. I need one.
Questions:
What is the diameter of the arc for the slots? Is there a ratio to the diameter of the plate? Your disk appears to be about 12" to 14" in diameter?
Most of us will to use a pivot guide or circle cutter for our routers to make the slots.
What is the source of the "rubber" grippers?
Do you think having a spigot on the back of the disk that fits into a set of large lathe chuck jaws will work?
 

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The link posted by Lew shows how to lay out the arcs.

I got the rubber from McMaster Carr. They are table leg tips for 1/2" legs. Home Depot has larger ones. Here's how I made them. I chucked a 1/2" hardwood dowel in my Nova chuck, with the dowel going through the spindle, and sticking about 1-1/2" out of the chuck. Glue the tip on with slow set CA glue, and drill through it and the dowel with a 1/4" bit in a chuck in the tailstock. Then carefully part off from the dowel. Move the dowel and repeat. The screws are 1/4-20 that run through them. I got the plastic 3 wing nuts from McMaster Carr as well as all the other hardware.
 

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Looks good! Funny enough, I designed one in Pro/Engineer CAD/CAM and then machined it on a CNC mill too. Still have it but not the Delta lathe (the noise of the cone pulleys was to much for me). I used rubber bottle stoppers form a hardware store that sells a lot of wine making equipment.
 

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thanks for letting us know about this one. great idea… just to figure out how to make one sans CNC.
 

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Thanks for the info. I have bookmarked the link and will attempt one after the holidays.

Scrappy
 
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